Germination inhibitor from the Japanese cedar Cryptomeria japonica

(1S,6R)-2,7(14),10-Bisabolatrien-1-ol-4-one was identified as a germination inhibitor from the methanol extract of Japanese cedar wood, Cryptomeria japonica. The occurrence of this compound in 1 g fresh wood was 2.0 mg, and showed a maximum of 60% germination inhibition at the dose of 20 mg/filter paper (157 microg/cm(2)) against both of lettuce and rice seeds for 4 d. A selective activity between Dicotyledoneae and Monocotyledoneae seeds was not observed.